Safety seat and safety arrangement of seats

ABSTRACT

In a motor vehicle, there are arranged abreast first and second seats. Each seat includes a seat cushion, a seatback pivotally connected to the seat cushion, and a power reclining device for pivoting the seatback to a desired angular position. A load transmitting center structure is mounted on the vehicle floor between the first and second seats. A manual switch is used which, when operated, pivots the seatback of the second seat to a desired angular position. At least the second seat has a reinforcing structure installed therein. The reinforcing structure exhibits the maximum performance in cooperation with the load transmitting center structure when the seatback of the second seat is within a given angular range. A computer-aided control device is used, which limits the angular position of the seatback of the second seat to the given angular range when the second seat carries thereon a seat occupant, and pivots the seatback of the second seat to an angular position coincident with that taken by the seatback of the first seat when the second seat carries thereon no seat occupant.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to safety seats, and moreparticularly to safety seats for automobiles, which can protect seatoccupants even when an associated motor vehicle encounters a side-oncollision or the like. More specifically, the present invention isconcerned with safety seats and safety arrangements of automotive seats.

2. Description of the Prior Art

In order to protect seat occupants upon a side-on vehicle collision,various seats have been hitherto proposed and put into practical use,some of which are disclosed in Japanese Patent Second ProvisionalPublication 61-35017 and Japanese Utility Model First ProvisionalPublication 3-26652.

In these disclosed seats, so-called "reinforcing members" are employedwhich are installed in seat cushions and/or seatbacks to reinforce them.With these reinforcing members, the mechanical strength of the seats isincreased, so that even when the associated motor vehicle is subjectedto a side-on vehicle collision, the seats are prevented from severedamage thereby protecting the seat occupants.

However, due to their inherent construction, such reinforced seats havesometimes failed to exhibit satisfactory performance against a severeside-on vehicle collision. Furthermore, due to presence of thereinforcing members therein, some of such reinforced seats have failedto provide seat occupants with a comfortable sitting feeling.

Furthermore, hitherto, the safety arrangement of such safety seats in amotor vehicle has been given little thought.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a safetyseat and a safety arrangement of seats which can assuredly protect aseat occupant or seat occupants even when an associated motor vehicle issubjected to a side-on vehicle collision.

According to a first aspect of the present invention, there is provideda seat arrangement in a motor vehicle having a vehicle floor. The seatarrangement comprises first and second seats arranged abreast on thevehicle floor, each seat including a seat cushion, a seatback pivotallyconnected to the seat cushion, and a power reclining device for pivotingthe seatback to a desired angular position relative to the seat cushionwith the aid of electric power; a load transmitting center structuremounted on the vehicle floor between the first and second seats; amanual switch which, when operated, pivots the seatback of the secondseat to a desired angular position with the aid of electric power; areinforcing structure installed in the second seat, the reinforcingstructure exhibiting the maximum performance in cooperation with theload transmitting center structure when the seatback of the second seatis within a given angular range; and control means for limiting theangular position of the seatback of the second seat to the given angularrange when the second seat carries thereon a seat occupant and forpivoting the seatback of the second seat to an angular positioncoincident with that taken by the seatback of the first seat when thesecond seat carries thereon no seat occupant.

According to a second aspect of the present invention, there is provideda safety seat which comprises a seat cushion including a seat cushionframe; a seatback pivotally connected to a rear end of the seat cushion,the seatback including a seatback frame; a reclining device forpermitting the seatback to assume a locked desired angular positionrelative to the seat cushion, the reclining device including aninside-positioned part and an outside-positioned part which are arrangedat both sides of the rear end of the seat cushion; and an elongatereinforcing structure secured to at least one of the seat cushion frameand the seatback frame, the reinforcing structure having axial endswhich face the inside-positioned and outside-positioned partsrespectively.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the present invention will becomeapparent from the following description when taken in conjunction withthe accompanying drawings, in which:

FIGS. 1 to 7 are drawings showing a first embodiment of the presentinvention, in which:

FIG. 1 is a perspective view of a driver's seat and an assistantdriver's seat, to which the present invention is applied;

FIG. 2 is a block diagram of a control system which controls the safetyseat arrangement of the first embodiment;

FIG. 3 is a rear view of both the driver's and assistant driver's seatswith some parts removed;

FIG. 4 is a perspective view of the assistant driver's seat with someparts removed;

FIG. 5 is a side view of the assistant driver's seat, showing a givenangular range "θ" within which the seatback of the seat is permitted topivot;

FIG. 6 is a table showing ON and OFF conditions of various sensing meanswith respect to angular position of the seatback; and

FIG. 7 is a flowchart showing operation steps programmed in a controlmeans employed in the first embodiment; and

FIGS. 8 to 10 are drawings showing a second embodiment of the presentinvention, in which:

FIG. 8 is a block diagram of a control system which controls the safetyseat arrangement of the second embodiment;

FIG. 9 is a side view of an assistant's drivers seat, showing an outsideload transmitting unit which can move forward and rearward by a positionshifter; and

FIG. 10 is a side view of the position shifter; and

FIG. 11 is a view similar to FIG. 3, but showing a safety seatarrangement of a third embodiment of the present invention;

FIGS. 12 to 19 are drawings showing a safety seat which is a fourthembodiment of the present invention, in which:

FIG. 12 is a front view of the seat of the fourth embodiment with someparts removed;

FIG. 13 is a side view of the seat with some parts removed;

FIG. 14 is a front view of framework of a seatback of the seat;

FIG. 15 is a side view of the framework of the seatback;

FIG. 16 is a perspective view of the seatback;

FIG. 17 is a partially sectioned view of a part of an elongatereinforcing structure employed in the seat;

FIG. 18 is a perspective view showing parts of the reinforcingstructure; and

FIG. 19 is a schematic view showing a condition wherein an associatedmotor vehicle is subjected to a side-on vehicle collision;

FIGS. 20 to 24 show a safety seat which is a fifth embodiment of thepresent invention, in which:

FIG. 20 is a front view of the seat of the fifth embodiment with someparts removed;

FIG. 21 is a side view of the seat with some parts removed;

FIG. 22 is an enlarged side view of a seat cushion frame of the safetyseat of the fifth embodiment;

FIG. 23 is an enlarged but partial plan view of the seat cushion frameof the safety seat of the fifth embodiment; and

FIG. 24 is a perspective view of the seat cushion of the safety seat ofthe fifth embodiment; and

FIGS. 25 and 26 show a safety seat which is a sixth embodiment of thepresent invention, in which:

FIG. 25 is a front view of the safety seat with some parts removed; and

FIG. 26 is a side view of the safety seat with some parts removed; and

FIGS. 27 and 28 show a safety seat which is a seventh embodiment of thepresent invention, in which:

FIG. 27 is a front view of the safety seat with some parts removed; and

FIG. 28 is a side view of the safety seat with some parts removed; and

FIG. 29 to 32 shows a safety seat which is a eighth embodiment of thepresent invention, in which:

FIG. 29 is a front view of the safety seat with some parts removed;

FIG. 30 is a side view of the safety seat with some parts removed;

FIG. 31 is an enlarged front view of a seatback frame of the safety seatof the eighth embodiment; and

FIG. 32 is an enlarged side view of the seatback frame; and

FIGS. 33 and 34 show a safety seat which is a ninth embodiment of thepresent invention, in which:

FIG. 33 is a front view of the safety seat with some parts removed; and

FIG. 34 is a side view of the safety seat with some parts removed; and

FIGS. 35 to 38 show a safety seat which is a tenth embodiment of thepresent invention, in which:

FIG. 35 is a front view of the safety seat with some parts removed;

FIG. 36 is a side view of the safety seat with some parts removed;

FIG. 37 is an enlarged front view of a seat cushion frame of the seatcushion of the tenth embodiment;

FIG. 38 is an enlarged side view of the seat cushion frame of the tenthembodiment; and

FIG. 39 is a drawing of an occupant on a seat, showing a desired areawhere a reinforcing structure according to the present invention shouldbe positioned.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 7, there is shown a safety seat arrangement of afirst embodiment of the present invention.

As will be seen from FIGS. 1 and 3, the safety seat arrangement of thefirst embodiment generally comprises a driver's seat 20a which includesa seat cushion 25 and a seatback 21, an assistant driver's seat 20(which will be referred to as assistant's seat) which is arranged besidethe driver's seat 20a and includes a seat cushion 25 and a seatback 21,a load transmitting center structure 11a which is arranged between thedriver's and assistant's seats 20a and 20, an occupant detecting means81 which is installed in the assistant's seat 20, an engine operationdetecting means 82, and a control unit 70. The driver's seat 20a and theassistant's seat 20 are equipped with seatback reclining devicesrespectively, the reclining device for the assistant's seat beingdesignated by numeral 30. As will be seen from FIG. 3, the seats 20 and20a are each equipped with a plurality of reinforcing beams 41, 42, 43,and 44, each extending laterally within the seatback 21 or the seatcushion 25.

The two seats 20 and 20a are mounted through respective seat slidedevices 13 (see FIG. 3) on a vehicle floor 10. Designated by numeral 11is a console which is arranged between the two seats 20 and 20a. Theload transmitting center structure 11a is positioned behind the console11. As will become apparent as the description proceeds, upon a side-onvehicle collision, one seat 20 or 20a is forced to abut against the loadtransmitting center structure 11a causing the latter to be tightlysandwiched between the two seats 20 and 20a. Thus, upon this, the impactforce applied to the seat 20 or 20a is transmitted to the other seat 20aor 20 through the load transmitting center structure 11a.

The load transmitting center structure 11a is constructed of a shockabsorbing material, such as a foamed aluminium, a rigid urethane foam, ahoneycomb structure member, or the like.

As will be understood from FIGS. 1 and 3, the load transmitting centerstructure 11a is so arranged and sized that each lateral side thereofcan face an inside lower end portion of the corresponding seatback 21even when, due to the work of the seat slide device 13, the seat takesits frontmost or rearmost position.

The seat slide device 13 comprises two rail units 13a and 13a which arearranged to support thereon lateral lower sides of the seat cushion 25of each seat. Each rail unit 13a comprises a stationary rail 15 which isfixed through leg members 16 to the vehicle floor 10, and a movable rail14 which is slidably engaged with the stationary rail 15 and supportsthereon the seat cushion 25.

As will be seen from FIGS. 3 and 4 which show the assistant's seat 20,the seatback 21 is pivotally connected to a rear end of the seat cushion25 through the reclining device 30. With this reclining device 30, theinclination angle of the seatback 21 relative to the seat cushion 25 isadjustable. The seat cushion 25 comprises a generally rectangular seatcushion frame 26 mounted on the rail units 13a and 13a, and the seatback21 comprises a generally U-shaped seatback frame 22.

As is seen from FIG. 4, the seatback frame 22 comprises two flat sidemembers 24 and 24 and a generally U-shaped upper member 23 which extendsbetween upper ends of the flat side members 24 and 24. First and secondparallel reinforcing beams 41 and 42 extend between lower portions ofthe flat side members 24 and 24. Similar to this, third and fourthreinforcing beams 43 and 44 extend between opposed side portions of theseat cushion frame 26. That is, the third reinforcing beam 43 ispositioned at a relatively rear part of the frame 26, while the fourthreinforcing beam 44 is positioned at a front end of the frame 26, asshown.

It is to be noted that driver's seat 20a has substantially the sameconstruction as the above-mentioned assistant's seat.

As is seen from FIG. 4, the reclining device 30 comprises two basemembers 32 which are secured to opposed rear ends of the seat cushionframe 26. The base members 32 have rear ends to which respective armmembers 31 are pivotally connected through pivot shafts 33. The armmembers 31 are secured to the flat side members 24 of the seat back 21.Thus, the seatback 21 can pivot about the pivot shafts 33 relative tothe seat cushion 25. Although not shown in FIGS. 1, 3, and 4, anelectric motor 33a (see FIG. 2) is employed for powering the recliningdevice 30, that is, for powering the arm members 31. The electric motor33a is controlled by the control unit 70.

As is best shown in FIG. 4, generally triangular load transmitting units50 and 50 are fixed to lateral sides of the seat cushion 25. As willbecome apparent as the description proceeds, upon a side-on vehiclecollision, these units 50 function to effectively transmit theabnormally big force, which has been just applied to the seat 20, to theload transmitting center structure 11a.

As is seen from FIG. 3, each load transmitting unit 50 comprises astructural base member 50a which has a generally U-shaped cross section,and three cross bars 51, 52, and 53 which are perpendicularly andtightly held by the structural base member 50a. As is seen from FIG. 4,the three cross bars 51, 52, and 53 are arranged coaxial with the first,second, and third reinforcing beams 41, 42, and 43 respectively. Eachload transmitting unit 50 is equipped with a cushion member 90 at a sidefacing the seat 20.

Referring to FIG. 2, there is shown a control system for the safety seatarrangement. The control unit 70 for controlling the power recliningdevice 30 of the assistant's seat 20 is a microcomputer which generallycomprises a central processing unit (CPU), a read only memory (ROM), anda random access memory (RAM). The computer has input and output devices71 and 72 connected thereto. The input device 71 has a seat occupantdetecting means 81, an engine operation detecting means 82, a manualswitch 83, an automatic switch 84, and a position limiting switch 85connected thereto.

The seat occupant detecting means 81 is a pressure sensor, which isinstalled in the seat cushion 25 of the assistant's seat 20, as shown inFIG. 1. That is, upon sensing a pressure due to sitting of a seatoccupant on the assistant's seat 20, the pressure sensor 81 is turned"ON". This "ON" is fed to the control unit 70.

The engine operation detecting means 82 is a switch which is turned "ON"when an ignition switch is turned "ON" by an ignition key.

The manual switch 83 is used for manually controlling the recliningdevice 30 and mounted on an inboard side of the seat cushion 25 of theassistant's seat 20. That is, by manipulating the manual switch 83, theelectric motor 33a of the reclining device 30 is controlled to force theseatback 21 to pivot to a desired angular position.

The automatic switch 84 is turned "ON" for a short period when theengine operation detecting means 82 is turned "ON". This will beunderstood from the table of FIG. 6. As will become apparent as thedescription proceeds, when the automatic switch 84 is turned "ON", theseatback 21 of the assistant's seat 20 is automatically pivoted to anangular position which coincides with that taken by the seatback 21 ofthe driver's seat 20a. That is, upon "ON" condition of the automaticswitch 84, the control unit 70 compares the inclination angle of theseatback 21 of assistant's seat 20 with that of the driver's seat 20a,and if there is any difference between them, the control unit 70actuates, through the output device 72, the electric motor 33a of thereclining device 30 by a degree corresponding to the difference therebyto move the seatback 21 of the assistant's seat 20 to the coincidentangular position. Upon completion of pivoting of the seatback 21 of theassistant's seat 20, the automatic switch 84 is turned " OFF".

As is seen from FIG. 2, the rotation of the electric motor 33a ismonitored by a sensor circuit 33b which comprises a reed switch. Thesensor circuit 33b feeds the control unit 70 with a pulse signal whichrepresents the number of rotations of the electric motor 33a. Byprocessing the pulse signal from the sensor circuit 33b, the controlunit 70 derives the desired angular position of the seatback 21 of theassistant's seat 20.

As is seen from the table of FIG. 6, the position limiting switch 85 isturned "ON" when both the engine operation detecting means 82 and theseat occupant detecting means 81 assume their "ON" positions. That is,upon receiving "ON" signal from the position limiting switch 85, thecontrol unit 70 determines a given angular range "θ" (see FIG. 5) withinwhich the seatback 21 of the assistant's seat 20 is permitted to pivotwhen the manual switch 83 is manipulated.

It is to be noted that when the seatback 21 of the assistant's seat 20is within the given angular range "θ", the inward end of the firstreinforcing beam 41 is directed to the load transmitting centerstructure 11a. Thus, when, with the seatback 21 of the assistant's seat20 kept within such range "θ", the impact force applied to the seat 20is assuredly transmitted to the center structure 11a through the firstreinforcing beam 41.

That is, when the position limiting switch 85 is turned "ON", thecontrol unit 70 limits the angular position of the seatback 21 of theassistant seat 20 within the given range "θ".

In the following, operation of the first embodiment will be describedwith reference to the drawings, particularly FIGS. 2, 3, and 7.

When, for starting the engine, the ignition switch is turned "ON" by theignition key, the engine operation detecting means 82 is turned "ON" andat the same time the input device 71 of the control unit 70 isenergized. That is, upon this, "ON" signal is fed to the control unit 70from the engine operation detecting means 82.

If, under this condition, the assistant's seat 20 has no occupantthereon, the seat occupant detecting means 81 is kept "OFF" (viz.,step-1 in FIG. 7). That is, "OFF" signal is fed to the control unit 70from the occupant detecting means 81.

As is seen from the table of FIG. 6 and the flowchart of FIG. 7, whenthe seat occupant detecting means 81 assumes "OFF" condition (step-1)and the engine operation detecting means 82 assumes "ON" condition(step-2), the control unit 70 actuates the power reclining device 30 topivot the seatback 21 of the assistant's seat 20 to an angular positionwhich is coincident with that of the seatback 21 of the driver's seat20a. More specifically, when the engine operation detecting means 82 isturned "ON" (step-2), the automatic switch 84 is turned "ON" for a shortperiod. Upon this, the control unit 70 measures the inclination angles(step-3and step-4) of the seatbacks 21 of the two seats 20 and 20a andcompares them (step-5), and if any difference is present therebetween,the control unit 70 actuates the electric motor 33a of the recliningdevice 30 to pivot the seatback 21 of the assistant's seat to thecoincident position (step-7).

When, with the seatback 21 of the assistant's seat 20 thus keptcoincident with the seatback 21 of the driver's seat 20a, the vehicleencounters a side-on vehicle collision applying an abnormally big forceto the door 12 (see FIG. 3) in the direction of the arrow F, the door 12is inwardly deformed and thus the big force is applied through theoutside triangular load transmitting unit 50 to the assistant's seat 20.The big force applied to the assistant's seat 20 is then applied throughthe inside triangular load transmitting unit 50 to the load transmittingcenter structure 11a and then through the inside triangular loadtransmitting unit 50 to the driver's seat 20a.

Because almost all of the impact big force applied to the side door 12is received by the assistant's seat 20, the center structure 11a, andthe driver's seat 20a, which constitute a united structure, the impactshock applied to the vehicle is effectively dampened.

It is to be noted that, due to the coincident positioning of theseatbacks 21 of the two seats 20 and 20a, the load transmission from theseatback 21 of one seat 20 to the seatback 21 of the other seat 20athrough the center structure 11a is effectively carried out.

Furthermore, because of provision of the various reinforcing beams 41,42, 43, and 44 which are installed, the seats 20 and 20a are preventedfrom being deformed or damaged.

These advantageous phenomena induce safety of the driver on the driver'sseat 20a.

When, under operation of the engine, a passenger sits on the assistant'sseat 20, the seat occupant detecting means 81 is turned "ON". Upon this,the position limiting switch 85 is turned "ON", as is understood fromthe table of FIG. 6. Thus, as has been described hereinabove, thecontrol unit 70 limits the angular position of the seatback 21 of theassistant's seat 20 to the given angular range "θ1" (see FIG. 5).

Thus, under this condition, the angular position of the seatback 21 ofthe assistant's seat 20 can not exceed the given angular range "θ1" evenwhen the manual switch 83 for the power reclining device 30 ismanipulated by the seat occupant. As has been described hereinafore,when the seatback 21 of the assistant's seat 20 is within the range "θ",the impact force applied to the seat 20, which is produced upon aside-on vehicle collision, is assuredly transmitted to the loadtransmitting center structure 11a through the first reinforcing beam 41.Thus, safety of the seat occupants on the two seats 20 and 20a isassured.

Referring to FIGS. 8 to 10, there is shown a safety seat arrangement ofa second embodiment of the present invention.

Since the second embodiment is similar to the above-mentioned firstembodiment, only parts and constructions which are different from thoseof the first embodiment will be described in detail in the following.

As is seen from FIG. 9, in the second embodiment, there is employed aposition shifter 60 for the outside load transmitting unit 50. That is,due to work of the position shifter 60, only the outside loadtransmitting unit 50 is moved along the axis of the associated seatcushion 25 between front and rear positions which are shown by solid andphantom lines respectively.

It is to be noted that the front position is the position which assuresthe effective transmission of the abnormally big force from the loadtransmitting unit 50 to the first, second, and third reinforcing beams41, 42, and 43 of the seat 20; while, the rear position is the positionwhich facilitates ingress and egress of a passenger for the seat 20.

As is understood from FIG. 10, the position shifter 60 comprises a nutmember 64 which is connected through a bracket 65 to the outside movablerail 14 of the seat 20. A threaded bolt 63 passes through the nut member64 while being meshed therewith. The threaded bolt 63 is powered orrotated by an electric motor 61 which is secured to the structural basemember 50a of the outside load transmitting unit 50. For reducing thespeed of rotation applied to the threaded bolt 63, a speed reductiongear unit 62 is interposed between the electric motor 61 and thethreaded bolt 63.

As is seen from FIG. 3, the structural base member 50a is equipped at aside facing the seat 20 or 20a with a cushion member 90.

Referring to FIG. 8, there is shown a control system for controlling thesafety seat arrangement of the second embodiment.

The control system comprises the seat occupant detecting means 81 whichcan detect whether the seat 20 carries thereon a seat occupant or not.Thus, the above-mentioned pressure sensor is used as the means 81. Ifdesired, a seatbelt switch, which is turned "ON" when a seat occupantwears a seatbelt, may be used as the means 81, which is disclosed inJapanese Utility Model Second Provisional Publication 62-117131. Theinformation signal produced by the seat occupant detecting means 81 isfed to a control unit 80 which is a microcomputer. As shown, instructionsignals produced by the control unit 80 are fed to both the electricmotor 33a of the reclining device 30 and the electric motor 61 of theposition shifter 60.

In the following, operation of the second embodiment will be describedwith reference to the drawings, particularly FIGS. 8 and 9.

When there is no occupant on the seat 20, the seat occupant detectingmeans 81 is kept "OFF". Under this condition, the outside loadtransmitting unit 50 assumes the rear position as shown by phantom linein FIG. 9. Thus, a passenger can easily sit on the seat 20.

When then the passenger actually sits on the seat 20, the seat occupantdetecting means 81 issues "ON" signal to the control unit 80. Upon this,the control unit 80 energizes the electric motor 61 of the positionshifter 60 and thus moves the outside load transmitting unit 50 from therear position to the front position which is shown by solid line in FIG.9. At the same time, the control unit 80 limits the angular position ofthe seatback 21 of the seat 20 within the afore-mentioned given range"θ". Thus, if the seatback 21 has been left beyond the given range "θ",the seatback 21 is automatically pivoted to a position within the range.Of course, thereafter, the angular position of the seatback 21 can beadjusted by manipulating a manual switch 83, but within the range "θ".

When the seat occupant leaves the seat 20, the seat occupant detectingmeans 81 is turned "OFF". Thus, the control unit 80 energizes the motor61 of the position shifter 60 to rotate in the opposite directionthereby moving the load transmitting unit 50 from the front position tothe rear position. At the same time, the control unit 80 cancels thelimitation of the angular position taken by the seatback 21 of the seat20.

Referring to FIG. 11, there is shown a safety seat arrangement of athird embodiment of the present invention.

The safety seat arrangement of this embodiment is substantially the sameas that of the second embodiment except the inside load transmittingunit which is denoted by numeral 50'. As shown, the unit 50' has alaterally extending part which abuts against the inside loadtransmitting unit 50 of the other seat 20a. Thus, in this embodiment,there is no need of providing a structure which corresponds to the loadtransmitting center structure 11a which is employed in the first andsecond embodiments.

Referring to FIGS. 12 to 19, there is shown a safety seat 110a which isa fourth embodiment of the present invention.

As is best shown in FIGS. 12 and 13, the safety seat 110a comprisesgenerally a seat cushion 120, a seatback 130, and a reclining device 150through which the seatback 130 is pivotally connected to a rear end ofthe seat cushion 120.

The seatback 130 has at its lower base portion a laterally extendingreinforcing structure 140a. As will be described in detail hereinafter,when, due to a side-on vehicle collision or the like, an abnormally bigforce is applied to an outside portion of the seat 110a, the force iseffectively transmitted to the inside portion of the seat through thereinforcing structure 140a.

The seat cushion 120 is mounted through a seat slide device 160 to avehicle floor "A". Thus, the seat 110a is movable in a fore-and-aftdirection relative to the floor "A". The seat slide device 160 comprisesa pair of rail units each including a stationary rail 161 which isconnected through leg members 163 and 164 to the vehicle floor "A" and amovable rail 162 which is slidably engaged with the stationary rail 161and supports thereon the seat proper 110a. Although not shown in thedrawings, the seat slide device 160 is equipped with a position locker,so that the seat 110a can be locked at a desired position.

As is best shown in FIGS. 14 and 15, the seatback 130 comprises arectangular back frame 131 constructed of a pipe member. That is, theback frame 131 comprises two side portions 133, a reversed U-shapedupper portion 132 which extends between upper ends of the side portions133, and a U-shaped lower portion 134 which extends between lower endsof the side portions 133.

As is best shown in FIG. 14, the elongate reinforcing structure 140a isconnected through two brackets 144 to the U-shaped lower portion 134 ofthe back frame 131. The reinforcing structure 140a extends in parallelwith the lower portion 134, as shown.

As is seen from FIGS. 14 and 17, the reinforcing structure 140acomprises a high resiliency elongate member 141, circular plates 142awelded to both ends of the elongate member 141, and elastic covers 143covering the circular plates 142a. As is seen from FIGS. 17 and 18, theelastic cover 143 is press-fitted to the circular plate 142a.

As is seen from FIGS. 14 and 15, between lower ends of the side portions133 of the back frame 131, there extends a trim cover catching wire138a. Although not shown in these drawings, a trim cover for theseatback 130 has a lower end caught by the wire 138a.

As is seen from FIG. 15, to the upper ends of the respective sideportions 133 of the back frame 131, there are fixed reinforcing plates136. Furthermore, as is seen from FIG. 14, to the side portions 133,there are fixed respective side plate members 133a between which aplurality of S-springs 137 extend. To the upper portion 132 of the backframe 131, there are fixed two holders 135 by which stays 130b (see FIG.12) of a head rest 130a are supported.

As is seen from FIG. 14, to each shoulder portion of the back frame 131,there is mounted a trim cover catching wire 138 by which an upperportion of the trim cover (not shown) is caught.

As is seen from FIGS. 12 and 13, the reclining device 150 comprisesgenerally base members 152 which are secured to laterally opposed sidesof a rear end of the seat cushion 120 and arm members 151 which arepivotally connected through respective pivot shafts 153 to the basemembers 152. The arm members 151 are connected to lower end portions ofthe side plate members 133a (see FIG. 15) of the back frame 131. Forthis connection, each side plate member 133a has nuts 139 weldedthereto. Although not shown in the drawings, the reclining device 150 isequipped with a position locker, so that the seatback 130 can be lockedat a desired angular position relative to the seat cushion 120.

As is seen from FIG. 13, the arm members 151 of the reclining device 150are positioned on axial extensions of the elongate member 141 of thereinforcing structure 140a. That is, each arm member 151 faces thecorresponding circular plate 142a fixed to the end of the elongatemember 141.

FIG. 19 shows the safety seat 110a which is used as a driver's seat in amotor vehicle. Designated by numeral 170 is an assistant driver's seatwhich is located beside the seat 110a. A console 171 is arranged betweenthe two seats 110a and 170. Although not shown in this drawing, a loadtransmitting center structure such as the afore-mentioned centerstructure 11a (see FIG. 1) is mounted behind the console 171.

As will be understood from FIG. 19, when, due to a side-on vehiclecollision with a vehicle "C", an abnormally big force is applied to adoor "B", the door "B" is inwardly deformed and pressed against theoutside portion of the seat 110a. Upon this, the outside-positionedparts of the reclining device 150 are deformed inward and brought intoabutment with the elongate reinforcing structure 140a, and thereinforcing structure 140a is pressed against the load transmittingcenter structure.

Because almost all of the abnormally big impact force applied to theside door "B" is received by the outside-positioned parts of thereclining device 150, the reinforcing structure 140a, theinside-positioned parts of the reclining device 150, and the loadtransmitting center structure, which constitute a united structure, theimpact shock applied to the vehicle is effectively dampened.

It is to be noted that due to provision of the reinforcing structure140a, durability of the seat 110a against such side-on vehicle collisionis remarkably increased.

Referring to FIGS. 20 to 24, there is shown a safety seat 110b which isa fifth embodiment of the present invention.

Since this embodiment is similar to the above-mentioned fourthembodiment, only parts and constructions which are different from thoseof the fourth embodiment will be described, and the same parts aredenoted by the same numerals.

In this fifth embodiment, the seat cushion 120b has at its rear endportion a laterally extending reinforcing structure 140b. The seatcushion 120b comprises a pan frame 121. The pan frame 121 has a rearportion 123 to which the reinforcing structure 140b is directlyconnected as is seen from FIGS. 22 and 23.

The elongate reinforcing structure 140b comprises a high resiliencyelongate member 141b and circular plates 142b welded to both ends of theelongate member 141b. As is seen from FIG. 24, the circular plates 142bare exposed to the outside of the seat cushion 120b.

As is seen from FIG. 21, in this fifth embodiment, each circular plate142b of the reinforcing structure 140b is positioned in the vicinity ofthe pivot shaft 153 of the reclining device 150 so that the axis of thepivot shaft 153 passes through the circular plate 142b. For achievingthis, as is seen from FIG. 22, an eccentric connection is made betweenthe circular plate 142b and the elongate member 141b. As is seen fromFIGS. 22 and 23, to front side portions of the cushion frame 121, thereare welded frame members 124 by which side portions of a pad member (notshown) of the seat cushion 120b are supported. Furthermore, to frontlower sides of the cushion frame 121, there are connected trim wires 125by which a trim cover (not shown) for the pad member is retained.

Due to provision of the elongate reinforcing structure 140b in the seatcushion 120b, substantially the same advantages as those of theabove-mentioned fourth embodiment are obtained in this fifth embodiment.

Referring to FIGS. 25 and 26, there is shown a safety seat 110c which isa sixth embodiment of the present invention.

In this sixth embodiment, two reinforcing structures 140a and 140b areused which are respectively mounted to the seatback 130 and the seatcushion 120b in such a manner as has been described in the fourth andfifth embodiments. That is, one reinforcing structure 140a is connectedthrough two brackets 144 to the lower portion 134 of the seatback frame131, and the other reinforcing structure 140b is connected to the rearportion of the pan frame 121 of the seat cushion 120b.

Due to usage of the two reinforcing structures 140a and 140b, durabilityof the seat 110c against the side-on vehicle collision is muchincreased.

Referring to FIGS. 27 and 28, there is shown a safety seat 110d which isa seventh embodiment of the present invention.

As is understood from FIG. 27, in this seventh embodiment, the backframe 131d of the seatback is constructed of a pipe member and comprisesside portions 133, a generally U-shaped upper portion 132 which extendsbetween upper ends of the side portions 133, and two mutuallyintersecting portions 141d which extend obliquely from lower ends of theside portions 133. The two intersecting portions 141d are welded attheir middle portions 134d and have at their leading ends circularplates 142d welded thereto. Each circular plate 142d faces theinside-positioned (or outside-positioned) part of the reclining device150.

Thus, the mutually intersecting portions 141d and the circular plates142d constitute a reinforcing structure 140d. Because the reinforcingstructure 140d is constructed by a part of the back frame 131d of theseatback 130d, the number of parts of the safety seat 110d can bereduced.

Referring to FIGS. 29 to 32, there is shown a safety seat 110e which isa eighth embodiment of the present invention.

As is well shown in FIGS. 29 and 31, in this embodiment 110e, the sideportions 133 of the back frame 131e have inwardly bent lower portions133b. The bent lower portions 133b have leading ends to which areinforcing structure 140e is directly fixed. The reinforcing structure140e comprises a high resiliency elongate member 141e welded to theleading ends of the lower portions 133b and two circular plates 142ewelded to respective ends of the elongate member 141e. Of course, eachcircular plate 142e fades the inside-positioned (or outside-positioned)part of the reclining device 150.

In this embodiment, the elongate member 141e of the reinforcingstructure 140e serves as a lower cross portion of the back frame 131e,which reduces the number of parts of the seat 110e.

Referring to FIGS. 33 and 34, there is shown a safety seat 110f which isa ninth embodiment of the present invention.

The seat 110f of this embodiment is substantially the same as theabove-mentioned fifth embodiment 110b except for the following.

That is, in this ninth embodiment, two reinforcing ribs 145 are weldedto the high resiliency elongate member 141f of the reinforcing structure140f near the circular plates 142f. Each rib 145 is triangular in shape,as shown. More specifically, two perpendicularly intersecting sides ofeach rib 145 are welded to the elongate member 141f and the circularplate 142f.

Due to provision of such reinforcing ribs 145, the mechanical strengthof the reinforcing structure 140f is increased, and thus the durabilityof the seat 110f against the side-on vehicle collision is muchincreased.

Referring to FIGS. 35 to 37, there is shown a safety seat 110g which isa tenth embodiment of the present invention.

In this embodiment, the reinforcing structure 140g is installed in theseat cushion 120g of the seat 110g. Designated by numeral 121 is thecushion frame of the seat cushion 120g.

As is seen from FIG. 36, the reinforcing structure 140g employed in thisembodiment is mounted to a rear end 123 of the cushion frame 121.

As is seen from FIGS. 35 and 37, the reinforcing structure 140gcomprises an inclined elongate member 146a and a horizontal elongatemember 146b. These two elongate members 146a and 146b are welded to twoplates 142g having circular portions at their respective ends.

When, as is understood from FIG. 37, an abnormally big force is appliedto the seat 110g in the direction of the arrow due to a side-on vehiclecollision, the force is effectively received by the reinforcingstructure 140g thereby preventing the seat 110g from being damaged.

Due to usage of the inclined elongate member 146a, the mechanicalstrength of the reinforcing structure 140g is much increased.

FIG. 39 shows a region "D" where the reinforcing structures 140a to 140gof the above-mentioned fourth to tenth embodiments should be positioned.As shown, the region "D" includes a rear end portion of the seat cushion120 and a lower end portion of the seatback 130.

What is claimed is:
 1. A safety seat comprising:a seat cushion includinga seat cushion frame; a seatback pivotally connected to a rear end ofsaid seat cushion, said seatback including a seatback frame; a recliningdevice for permitting said seatback to assume a locked desired angularposition relative to said seat cushion, said reclining device includingan inside-positioned part and an outside-positioned part which arelocated at both sides of the rear end of said seat cushion, each partincluding a base member secured to said seat cushion frame, an armmember secured to said seatback frame, and a pivot shaft for pivotallyconnecting said base and arm members; first and second elongate members,each elongate member being constructed of a high resiliency material andextending laterally in a space defined between said inside-positionedand outside-positioned parts; securing means for securing said first andsecond elongate members to one of said seat cushion frame and saidseatback frame; a first plate secured to first ends of said first andsecond elongate members, said first plate facing said base member ofsaid inside-positioned part; and a second plate secured to second endsof said first and second elongate members, said second plate facing saidbase member of said outside-positioned part; wherein one of said firstand second elongate members is inclined relative to the other.
 2. Asafety seat as claimed in claim 1, in which said securing meanscomprises a pan frame through which said first and second elongatemembers are secured to said seat cushion frame.
 3. A safety seat asclaimed in claim 1, wherein each of said first and second plates facessaid base member of a corresponding inside or outside-positioned part ofsaid reclining device with a given clearance therebetween.